I think the greatest issue with Less Wrong is that it lacks direction.

I'm not sure "direction" is the right phrase. It's not like Eliezer told other people what posts to write--he had a goal and a thing to explain, and then he explained it. People didn't read his posts because he had authority; they read his posts because someone recommended them as being useful and interesting.

And similarly, I don't think the absence of roles is the issue: I think it's the absence of time and topics. Maybe there are people with something to write who aren't writing it because of some block that a clearly visible person could help remove--but it seems more likely to me that there are people with something to say but no time to say it, or with the time to write posts but little to talk about, and there are fewer intersections of those two as time goes on.